The present invention relates to apparatus for automatically applying carriers to sets of containers in a high speed, continuous-flow packaging operation and, more particularly, to a carrier applicator having improved means for insuring positive engagement of the containers on the carrier.
Liquid containers such as glass or plastic bottles and jars in which carbonated beverages, juices, fruit drinks and the like are packaged, are often sold in multiples as a unit containing six, eight or twelve containers each. In order to maintain the containers as a unit and to protect the containers from damage and dirt during shipping, as well as to provide a convenient way to handle the containers, a carrier is often provided for the containers. The carriers have, in the past, commonly been formed of a paper product, such as cardboard, but more recently, carriers composed of plastic material have been utilized because same are inexpensive to manufacture and are of relatively high strength.
The structure of plastic carriers designed to accommodate multiple containers are known in the art and have been the subject of various patents, such as U.S. Pat. No. 3,871,699 entitled "Plastic Jacket For Containers", issued Mar. 18, 1975, and U.S. Pat. No. 3,912,075 entitled "Plastic Carrier For Containers", issued Oct. 14, 1975. The carrier commonly consists of a one-piece thermally formed plastic receptacle designed to enclose and engage the upper portion of each of the containers. The carrier is formed with a number of compartments, each of which is contoured in accordance with the upper portion of the container. Each container is inserted into and suspended from a recess in the compartment in "snap-fit" fashion, by seating a plurality of projections, extending inwardly from the recess, below a radial bulge or flange situated on the neck of the container.
On certain types of containers, an annular protrusion or flange is situated on the neck of the container immediately below the area upon which the cap or closure is placed. On other types of containers, the cap or closure has an inwardly directed bottom portion which surrounds the annular projection or flange on the container and which is designed to be broken away when the cap or closure is twisted off the container. In either case, the neck of the container is provided with an annular projection or flange which has a diameter greater than the section of the neck of the container immediately below same.
Each of the recesses in the carrier, into which the upper portion of a container will be received, is provided with a set of diametrically opposed, inwardly extending projections, which are preferably formed integrally with the carrier. The projections are, to some extent, flexible, such that as the top of the container is received within the recess, the flange or cap on the container will cam the projections out of the way. When the container is fully inserted within the recess, the resiliency of the projections causes same to lodge below the flange so as to engage the container and secure same to the carrier.
In order to insure that the containers will not dislodge from the carrier, it is necessary that each of the projections extending from each recess be correctly situated below the container flange. In order to seat the projections below the flange, it is necessary to support the containers and exert a downwardly directed force on the carrier, at a point thereon immediately adjacent each projection. However, in practice, it is difficult to exert the necessary downwardly directed forces on the carrier in the immediate vicinity of the projections adjacent the outer periphery of the carrier, because of the contours of the carrier.
More specifically, each compartment in the carrier is shaped or contoured in accordance with the shape of the upper portion of the container which same is designed to receive. Each compartment has a planar top surface upon which the container receiving recess is situated. Between the recess and the outer peripheral edge of the top surface is located a relatively narrow shoulder. The carrier is contoured such that the side thereof extends downwardly at a steep angle from the shoulder. Thus, in order to exert a downward force on the carrier immediately adjacent the projections along the outer periphery thereof, it is necessary to exert the force on the relatively narrow shoulder of the carrier. However, it is difficult to engage the shoulder of the carrier from above because the flange on the container obstructs all but the very narrow edge of the shoulder from above.
It is therefore extremely difficult to devise a system capable of engaging the shoulder from above and exerting the necessary downwardly directed forces thereon which are required to positively seat all of the projections below the flange of the container in every instance. It is even more difficult to perform this function when the operation is fully automated, particularly in a high-speed, continuous-flow packaging operation.
One attempt to provide an automated carrier applicator has been made by Owens-Illinois in its Model 104-200 carrier applicator. In this device, the containers are aligned on a first conveyor and the carriers flow along a second conveyor which is situated above the first. As the containers move along the first conveyor, a carrier is dispensed from the second conveyor and placed on top of the containers with the recesses in the carrier in alignment with the tops of the containers. The container-carrier assembly is then conveyed beneath a rotatable cylinder which has pairs of spaced apertures situated along the surface thereof. Each pair of apertures is spaced from the adjacent pair a distance which is substantially equal to the distance between the pairs of recesses on the carrier. In this manner, as the container-carrier assembly is conveyed beneath the cylinder, the cylinder rotates, the protruding container tops are received within the apertures on the cylinder surface and the surface of the cylinder exerts a downwardly directed force on the top surface of the carrier so as to seat the projections below the container flanges.
It has been found that this system performs satisfactorily with respect to the projections adjacent the central portion of the carrier top surface because there is sufficient area on the top surface of the carrier adjacent these projections to permit substantial contact between the surface of the cylinder and the surface of the carrier. However, the same is not true with respect to the projections along the outer periphery of the top surface of the carrier because there exists in these areas only a narrow shoulder, partially obstructed from above by the flange, upon which the forces may be applied. Precise alignment between the cylinder surface and the narrow shoulder of the carrier is required if the necessary downward force is to be exerted on the shoulder to seat the projections adjacent thereto. To further compound the problem, the apertures in the cylinder surface must be somewhat larger in diameter than the flanges. This is necessary to provide sufficient clearance for the container tops to be received within the apertures, as the cylinder rotates. It is, therefore, extremely difficult to positively cause the cylinder surface to adequately engage the narrow shoulder along the outer peripheral edge of the carrier. Thus, with the system proposed by Owens-Illinois, the projections adjacent the narrow shoulder, along the outer peripheral surface of the carrier, are often not correctly positioned below the container flange. When this occurs, the containers become dislodged from the carrier during shipping and handling, thereby negating the advantages of the use of the carrier.
It is, therefore, a prime object of the present invention to provide a carrier applicator wherein positive engagement of each container on the carrier is insured.
It is a further object of the present invention to provide a carrier applicator having improved means for positively seating the engaging means adjacent the outer periphery of the carrier.
It is a further object of the present invention to provide a carrier applicator which can be utilized in automated high-speed, continuous-flow packaging operations.
It is a further object of the present invention to provide a carrier applicator which utilizes concave deformable discs to accommodate the curvature of the containers and to permit increased contact with the narrow shoulder of the carrier.
It is a further object of the present invention to provide a carrier applicator wherein downwardly directed forces of progressively increasing magnitude are applied to the carrier.
It is a still further object of the present invention to provide a carrier applicator which is composed of relatively simple, inexpensive parts which function together in a reliable manner.
In accordance with the present invention, apparatus is provided for applying a carrier on a container. The container is of the type having a flange thereon below which means on the carrier are adapted to engage the container. The apparatus comprises means for placing a carrier on a container to form an assembly with the engaging means at least partially situated above the flange and means for seating the engaging means below the flange. The seating means comprises a deformable disc, means for moving the assembly along a path relative to the disc and means for rotatably mounting the disc in alignment with the path of movement of the assembly with at least a portion of the disc positioned to intersect the plane of the flange. In this manner, the disc contacts the assembly and is deformed by the container as the assembly is moved, so as to accommodate the contour of the container and applies a force on a sufficient area of the carrier to seat the engaging means below the flange.
The container has a curved surface. The mounting means comprises means for positioning the disc to contact the curved container surface and at least partially assume a curvature determined by the curved surface while in contact therewith. The disc is preferably concave in configuration and, thus, has a concave side. The disc positioning means positions the disc with the concave side facing the curved surface. The deformation of the disc permits the rim of the disc to positively engage the narrow shoulder along the outer periphery of the carrier over a substantially increased surface area.
Situated between the assembly forming means and the concave disc, along the path of movement of the assembly, are second and third planar discs. Means are provided for rotatably mounting the second disc, for contact with the assembly, a given distance from the moving means. Means are provided for rotatably mounting the third disc, for contact with the assembly, at a distance less than the given distance from the moving means. In this manner, the second and third discs exert progressively increasing forces on the carrier as same is moved along its path of movement.
Thus, after the carrier is properly positioned on top of the containers, the containers are moved along a path by a conveyor and passed beneath sets of planar rotatable discs, preferably also deformable, which exert progressively increasing downwardly directed forces on the carrier to cause the engaging means situated along the central portion of the top surface of the carrier, and, in some instances, certain of the engaging means situated along the outer periphery of the top surface of the carrier, to be seated beneath the flanges on the carriers. The planar discs, although also preferably composed of deformable material and thus designed to accommodate the contours of the containers to a certain extent, normally deform in a manner which provides insufficient contact area between the rims thereof and the narrow shoulder along the outer periphery of the top surface of the carrier. Thus, the engaging means adjacent the outer periphery of the top surface of the carrier may not be positively seated below the flanges on the adjacent containers by the planar discs.
For this reason, the final set of deformable rotatable discs has a dish-shaped or concave structure such that same may more readily accommodate the curvature of the containers and the rims thereof will contact the narrow shoulder of the outer periphery of the top surface of the carrier over a sufficient surface area to insure that the engaging means on the outer periphery of the top surface of the carrier are positively seated below the container flanges.